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Finding the Fourth Proportional to 885.90, 1,328.88 and 399

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Solution

The fourth proportional to 885.90, 1,328.88 and 399 is: 598.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    885.90 : 1,328.88 = 399 : x
  2. Step 2: Convert to fraction form
    885.90/1,328.88 = 399/x
  3. Step 3: Cross multiply
    885.90x = 1,328.88 × 399
  4. Step 4: Simplify right side
    885.90x = 530,223.12
  5. Step 5: Solve for x
    x = 530,223.12/885.90
  6. Step 6: Final answer
    x = 598.51

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.